1. Field of the Invention
The present invention relates to a substrate processing apparatus configured to perform a variety of processes such as an oxidation process, a diffusion process, and a thin film forming process on a substrate such as a wafer, and more particularly, to a substrate processing apparatus capable of displaying the state of gas flow in a gas pipe.
2. Description of the Prior Art
A substrate processing apparatus includes an airtight process chamber and is used to manufacture a semiconductor device by performing a process such as a pattern forming process on a wafer by supplying various gases to the process chamber to form a thin film on the wafer or supplying etch gas to the process chamber to etch the thin film.
Therefore, numbers of systems of gas supply lines and an exhaust system are connected to the process chamber of the substrate processing apparatus.
In addition, the substrate processing apparatus includes a control unit configured to control the gas supply lines and the exhaust system, and an indication unit equipped manipulation unit configured to indicate wafer processing states of the process chamber or gas supply states of the gas supply lines and the exhaust system.
Informations such as wafer processing states, pressure detection states of pressure gauges, flow detection states of flow controllers, and operation states of electromagnetic valves are sent from the control unit to the indication unit.
The plurality of gas supply lines are connected to the process chamber, and gas supply electromagnetic valves and interlock electromagnetic valves are closed or opened according to processing states under the control of the control unit, or by manipulating the indication unit.
In addition, the indication unit includes a gas monitoring indication unit configured to indicate gas supply states, and the indication unit is configured to indicate opening/closing states of the electromagnetic valves of the respective gas supply lines, and the indication unit is configured to inform that gas is supplied to the process chamber from which of gas pipes.
In addition, electromagnetic valves used to control flows of gases, where danger is caused by mixture, are controlled by an interlock operation of a central processing unit (CPU) of the control unit so as to prevent simultaneous opening of the electromagnetic valves.
As explained above, in the conventional substrate processing apparatus, flow states of the respective gas supply lines can be known from opening/closing states of the electromagnetic valves and flow detection results by the flow controllers.
That is, as shown in FIG. 8, a gas supply electromagnetic valve 2 and an interlock electromagnetic valve 3 are sequentially placed from the upstream side of a gas pipe 1. Gas is supplied to a section (a) flows to sections (b) and (c) through a regulator 4, and if the gas supply electromagnetic valve 2 is opened, the gas flows to a section (d). In this state, if a flow controller (Mass Flow Controller, MFC) 5 is controlled, the gas reaches a section (e), and then the gas flows to a section (f) in the same sequence.
If the electromagnetic valves 2 and 3 are opened simultaneously or sequentially from the upstream side, gas can be supplied to a tube (or process chamber) as intended. However, if it is forgotten whether the electromagnetic valves 2 and 3 are opened and the MFC 5 is controlled, it cannot be known whether gas flows to the tube. That is, only after the electromagnetic valves 2 and 3 are actually opened, the gas state of the gas pipe 1 can be ascertained.
Therefore, in the conventional art, since only the state of arriving gas is indicated, it cannot be known how gas flows in a pipe before an electromagnetic valve is opened.
In addition, since toxic or flammable gas is often used in a semiconductor manufacturing process, it may be dangerous to the human body if such gas is carelessly supplied, and a substrate processing process may be greatly affected if gas does not flow through an intended passage.
[Patent Document 1]    Japanese Unexamined Patent Application Publication No. 2002-25918